Federal, state and local agents raided 54 locations in Anaheim and in Los Angeles County, arresting 33 people to cap a yearlong investigation of the East Side Anaheim gang, police Sgt. Bob Dunn said.
Another 20 to 25 people already were in custody and several more were still being sought, he added.
Some of the raids concentrated on a poor, mainly Latino neighborhood known as Anna Drive where there has been a recent rise in gang activity, authorities said.
That is the neighborhood where police shot and killed Manuel Diaz, a reputed gang member who was unarmed, on July 21.
The next night, police shot and killed suspected gang member Joel Acevedo after he reportedly shot at an officer.
The killings prompted four days of violent demonstrations and a $50 million wrongful death lawsuit by Diaz's family.
Mug shots of some reputed suspects were displayed at the news conference Friday. One was named Manuel Diaz but police declined to say whether he was the same Diaz who was shot.
The raids were not related to the shootings and authorities even considered delaying them to avoid that appearance, police Chief John Welter said.
"We didn't want to be seen as coming in now and arresting a bunch of community members and having people misunderstand or again spread rumors and false information about what we were doing," he said.
"We need to regain some of the trust that has been lost as a result of some of these actions in the street by protesters," Welter said.
The gang is suspected of drug-dealing and murder and those facing federal or state drug and weapons charges could face up to 10 years in prison if convicted, authorities said.
Televised reports showed a line of men, some shirtless, sitting on the curb with their hands bound behind their backs.
During the yearlong investigation dubbed Operation Halo, authorities also seized 11 pounds of crystal methamphetamine and 40 guns, including assault-style rifles, sawed-off shotguns and a pistol believed used in a killing, authorities said.
The investigation was prompted by the 2011 stabbing death of a 12-year-old member of a graffiti tagging crew that is considered a "feeder" for the street gang, Dunn said.
Prosecutors say Juan Martinez was walking home from school when he was stabbed during a fight with a member of a rival tagging crew. Bryan Ocampo is charged with murder.
Violent crime in Anaheim, home of Disneyland and the Angels baseball team, jumped 10 percent last year and the number of murders nearly doubled, according to FBI crime statistics.